/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.preference;

import com.example.android.apis.R;

import android.content.Context;
import android.content.res.TypedArray;
import android.os.Parcel;
import android.os.Parcelable;
import android.preference.Preference;
import android.util.AttributeSet;
import android.view.View;
import android.widget.TextView;

/**
 * This is an example of a custom preference type. The preference counts the
 * number of clicks it has received and stores/retrieves it from the storage.
 */
public class MyPreference extends Preference {
	private int mClickCounter;

	// This is the constructor called by the inflater
	public MyPreference(Context context, AttributeSet attrs) {
		super(context, attrs);

		setWidgetLayoutResource(R.layout.preference_widget_mypreference);
	}

	@Override
	protected void onBindView(View view) {
		super.onBindView(view);

		// Set our custom views inside the layout
		final TextView myTextView = (TextView) view
				.findViewById(R.id.mypreference_widget);
		if (myTextView != null) {
			myTextView.setText(String.valueOf(mClickCounter));
		}
	}

	@Override
	protected void onClick() {
		int newValue = mClickCounter + 1;
		// Give the client a chance to ignore this change if they deem it
		// invalid
		if (!callChangeListener(newValue)) {
			// They don't want the value to be set
			return;
		}

		// Increment counter
		mClickCounter = newValue;

		// Save to persistent storage (this method will make sure this
		// preference should be persistent, along with other useful checks)
		persistInt(mClickCounter);

		// Data has changed, notify so UI can be refreshed!
		notifyChanged();
	}

	@Override
	protected Object onGetDefaultValue(TypedArray a, int index) {
		// This preference type's value type is Integer, so we read the default
		// value from the attributes as an Integer.
		return a.getInteger(index, 0);
	}

	@Override
	protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
		if (restoreValue) {
			// Restore state
			mClickCounter = getPersistedInt(mClickCounter);
		} else {
			// Set state
			int value = (Integer) defaultValue;
			mClickCounter = value;
			persistInt(value);
		}
	}

	@Override
	protected Parcelable onSaveInstanceState() {
		/*
		 * Suppose a client uses this preference type without persisting. We
		 * must save the instance state so it is able to, for example, survive
		 * orientation changes.
		 */

		final Parcelable superState = super.onSaveInstanceState();
		if (isPersistent()) {
			// No need to save instance state since it's persistent
			return superState;
		}

		// Save the instance state
		final SavedState myState = new SavedState(superState);
		myState.clickCounter = mClickCounter;
		return myState;
	}

	@Override
	protected void onRestoreInstanceState(Parcelable state) {
		if (!state.getClass().equals(SavedState.class)) {
			// Didn't save state for us in onSaveInstanceState
			super.onRestoreInstanceState(state);
			return;
		}

		// Restore the instance state
		SavedState myState = (SavedState) state;
		super.onRestoreInstanceState(myState.getSuperState());
		mClickCounter = myState.clickCounter;
		notifyChanged();
	}

	/**
	 * SavedState, a subclass of {@link BaseSavedState}, will store the state of
	 * MyPreference, a subclass of Preference.
	 * <p>
	 * It is important to always call through to super methods.
	 */
	private static class SavedState extends BaseSavedState {
		int clickCounter;

		public SavedState(Parcel source) {
			super(source);

			// Restore the click counter
			clickCounter = source.readInt();
		}

		@Override
		public void writeToParcel(Parcel dest, int flags) {
			super.writeToParcel(dest, flags);

			// Save the click counter
			dest.writeInt(clickCounter);
		}

		public SavedState(Parcelable superState) {
			super(superState);
		}

		public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() {
			public SavedState createFromParcel(Parcel in) {
				return new SavedState(in);
			}

			public SavedState[] newArray(int size) {
				return new SavedState[size];
			}
		};
	}

}
